Removing Item from collection and update toolbar - [Hide out of stock item in layer navigation ( configurable )]

Question

I'm trying to hide out of stock products in layer navigation. This can be done using this code: http://colin.mollenhour.com/2009/07/14/hiding-out-of-stock-items-in-layered-navigation/

The issue is that the above code is not filtering out of stock for configurable products:
Suppose I have a configurable product based on size and all the simple for that size are are out of stock ... the product is not filtered ( as for Coling comment this is difficult to implement because of OO query implementation )

So I would like to use a not pure SQL approach removing products from collection "on the fly" (this is expensive in performance but let say I don't care) ...

... at this point the issue is that the toolbar is still showing all the products count ... any way to workarround this issue ?

Thanks

Answer 1

I cannot find a precise a solution for the toolbar problem unless changing and overriding many magento files (template/block mainly).

Finally I figured out that the best approach was to find the products that I want to exclude and add a filter to the main collection filtering them out, in this way the toolbar doesn't suffer any problem:

$collection->getSelect()
                ->where('e.entity_id NOT IN (?)', $remove_ids);